Tungsten-cerium alloy wire and method for manufacturing the same

Abstract

The application belongs to the technical field of tungsten material manufacturing, and particularly relates to a tungsten-cerium alloy wire and a preparation method thereof. The preparation method comprises the following steps: mixing a cerium-containing solution and ammonium paratungstate by using a spray mixing method, drying to obtain a mixture; calcining the mixture at <=900 DEG C, and reducing in a hydrogen atmosphere at 800-1050 DEG C to obtain cerium-containing tungsten powder; isostatic pressing the cerium-containing tungsten powder, and sintering in a hydrogen atmosphere at 1500-1600 DEG C for 1-1.5 h, and then sintering at 2300-2450 DEG C for 5-8 h to obtain a tungsten rod; rolling, electric pulse treatment, forging and wire drawing treatment are performed on the tungsten rod to obtain a tungsten-cerium alloy wire with a diameter of 20-28 mu m. The application realizes uniform distribution of cerium elements in the alloy wire through solid-liquid cerium doping; the two-stage sintering process improves the density and mechanical properties of the tungsten rod; the prepared tungsten-cerium alloy wire has excellent tensile strength, high elongation and excellent fatigue resistance, and exhibits low edge collapse rate, low broken line rate and high service life in silicon nitride ceramic substrate cutting.

Description

Technical Field

[0001] This application belongs to the field of tungsten material manufacturing technology, specifically a tungsten-cerium alloy wire and its preparation method. Background Technology

[0002] With the explosive growth in demand from the new energy and semiconductor industry chains, third-generation semiconductors are developing rapidly. Silicon nitride (Si3N4) ceramic substrates, with their superior overall performance, are rapidly penetrating multiple high-tech fields. Some companies have already begun using silicon nitride substrates to package third-generation semiconductor devices, indicating that silicon nitride substrates are poised for a golden age of development.

[0003] Currently, diamond wires used for cutting silicon nitride ceramic substrates typically use high-strength high-carbon steel wire or nickel-plated steel wire as the matrix material. While high-carbon steel wire or nickel-plated steel wire is less expensive and technologically mature, it has significant mechanical performance defects during application. First, silicon nitride ceramics have extremely high hardness (HV10≈16~18GPa), requiring high tension to maintain stability during cutting. The tensile strength of high-carbon steel wire (typically ≤3500MPa) is prone to fatigue fracture under long-term high loads, leading to cutting interruptions and reduced yield. Second, high-carbon steel wire has low rigidity, making it prone to vibration during high-speed cutting, resulting in micro-chipping or beveling at the cut edge, affecting the dimensional accuracy of the silicon nitride ceramic substrate and subsequent packaging performance. Furthermore, high-carbon steel wire has low toughness, making it prone to brittle fracture when repeatedly cutting hard materials, resulting in a short service life. Summary of the Invention

[0004] To address the problems of low tensile strength, low toughness, high breakage rate, and low cutting precision leading to chipping of cut edges in high-carbon steel wire, this application provides a tungsten-cerium alloy wire and its preparation method. A tungsten-cerium alloy with uniform cerium distribution is prepared through a solid-liquid cerium-doped mixture and a synergistic sintering process. The resulting tungsten-cerium alloy wire exhibits excellent comprehensive properties, including superior tensile strength and toughness. It significantly reduces chipping or beveling during the cutting of silicon nitride ceramic substrates and also significantly improves service life compared to high-carbon steel wire.

[0005] According to a first aspect of this application, this application provides a method for preparing tungsten-cerium alloy wire, comprising the following steps:

[0006] S1. A cerium-containing solution is mixed with ammonium paratungstate using a spray mixing method, and then dried to obtain a mixture;

[0007] S2. The mixture is calcined to obtain oxide composite powder, wherein the calcination temperature is ≤900℃;

[0008] S3. The oxide composite powder is reduced in a hydrogen atmosphere to obtain cerium-tungsten powder. The reduction temperature is 800~1050℃ and the time is 3~3.5h.

[0009] S4. The cerium-containing tungsten powder is subjected to isostatic pressing to obtain a pressed blank;

[0010] S5. The pressed blank is sintered in a hydrogen atmosphere to obtain a tungsten rod. The segmented sintering includes a first stage sintering and a second stage sintering. The temperature of the first stage sintering is 1500~1600℃ and the time is 1~1.5h. The temperature of the second stage sintering is 2300~2450℃ and the time is 5~8h.

[0011] S6. The tungsten rod is rolled, subjected to electrical pulse treatment, forged and drawn to obtain a tungsten-cerium alloy wire with a diameter of 20~28μm.

[0012] In the above technical solution, step S1 uses a spray mixing method to uniformly disperse the cerium-containing solution in ammonium paratungstate (APT), achieving a highly uniform distribution of cerium in the tungsten matrix. Step S2 involves calcining the mixture to obtain an oxide composite powder containing cerium oxide and tungsten oxide. Cerium oxide is obtained by the oxidation of cerium, while tungsten oxide is obtained by the thermal decomposition of APT. Calcination at temperatures ≤900℃ results in small tungsten oxide particles, leading to small reduced tungsten powder particles. This small particle size helps suppress grain boundary diffusion during sintering, preventing porosity in the sintered rod. Excessive calcination temperature makes it difficult to control the crystal structure of tungsten oxide, thus altering the properties of the tungsten powder. Step S3 uses hydrogen to reduce the tungsten oxide in the oxide composite powder to tungsten powder. The reduction temperature is 800~1050℃, and the time is 3~3.5h. Too low a temperature or too short a time will result in insufficient reduction of tungsten oxide, leading to impure tungsten powder and increased brittleness during subsequent alloy wire preparation. Too high a temperature or too long a time will increase unnecessary consumption. Step S5 involves a two-stage sintering process on the compact prepared in step S4 within a hydrogen atmosphere. The first stage reduces the tungsten oxides formed during compact preparation at a relatively low temperature (1500~1600℃), lowering the oxygen content in the tungsten rod. The second stage utilizes a high temperature (2300~2450℃) for densification sintering, improving density and mechanical properties. Step S6 combines rolling, electro-pulse treatment, forging, and wire drawing to prepare the tungsten rod into a qualified tungsten-cerium alloy wire. The electro-pulse treatment helps reduce the internal stress of the tungsten rod.

[0013] Furthermore, step S1 also includes preparing the cerium-containing solution using a soluble cerium salt, wherein the mass fraction of cerium in the cerium-containing solution is 6.5% to 10%, and the mass ratio of the cerium-containing solution to the ammonium paratungstate is 0.24:1 to 0.36:1;

[0014] Low cerium content cannot suppress excessive growth of tungsten grains during annealing, increasing the brittleness of tungsten-cerium alloy wire; high cerium content excessively suppresses recrystallization of tungsten grains during annealing, reducing tensile strength after deformation. Therefore, high tensile strength tungsten-cerium alloy wire can be obtained by adjusting the cerium content to the optimal range.

[0015] Furthermore, the soluble cerium salt includes Ce(NO3)3·6H2O, and the cerium-containing solution includes cerium nitrate solution.

[0016] Furthermore, in step S1, the drying temperature is 70~90℃.

[0017] Furthermore, in step S2, the calcination includes a first stage calcination, a second stage calcination, and a third stage calcination, wherein the temperature of the first stage calcination is 200~220℃ and the time is 1.5~2h, the temperature of the second stage calcination is 350~400℃ and the time is 2~2.5h, and the temperature of the third stage calcination is 750~900℃ and the time is 3~4h.

[0018] The first stage of calcination is mainly to remove water of crystallization; in the second stage of calcination, cerium is fully oxidized into cerium oxide; in the third stage of calcination, APT is decomposed into tungsten oxide. At this time, the cerium oxide obtained from the second stage of calcination will be distributed at the grain boundaries of tungsten grains, forming a pinning effect, thereby inhibiting the growth of tungsten grains. Therefore, the size of tungsten grains can be adjusted by three-stage calcination.

[0019] Furthermore, in step S3, the flow rate of hydrogen in the hydrogen atmosphere is 20~28 L / min.

[0020] Furthermore, in step S4, the pressure during isostatic pressing is 170~200MPa.

[0021] Furthermore, in step S5, the flow rate of hydrogen in the hydrogen atmosphere is 3~5 L / min.

[0022] Furthermore, in step S6, the rolling temperature is 1400~1800℃;

[0023] The temperature during the electrical pulse processing is 700~900℃, and the time is 23~26s;

[0024] The feeding speed during the forging process is 1.2~3m / min, and the forging speed is 1500~2400 times / min.

[0025] Furthermore, in step S5, the diameter of the tungsten rod is 19.5 ± 0.3 mm;

[0026] In step S6, the diameter of the tungsten rod after rolling is 9±0.2mm;

[0027] In step S6, the diameter of the tungsten rod after forging is 3.6 ± 0.2 mm.

[0028] According to a second aspect of this application, this application provides a tungsten-cerium alloy wire, which is obtained by the above-described method for preparing tungsten-cerium alloy wire.

[0029] Furthermore, the tungsten-cerium alloy wire has a tensile strength ≥4800MPa and an elongation of 3%~15%.

[0030] Furthermore, the tungsten-cerium alloy wire has a tensile strength ≥6500MPa and an elongation of 8%~15%.

[0031] This application proposes a tungsten-cerium alloy wire and its preparation method, which produces the following beneficial effects: by solid-liquid doping with cerium, the uniform distribution of cerium in the alloy wire is achieved, overcoming the problems of uneven cerium distribution and easy agglomeration in the traditional mechanical mixing method; through a two-stage sintering process, the oxygen content in the tungsten rod is significantly reduced, and the density and mechanical properties are improved; the prepared tungsten-cerium alloy wire has excellent tensile strength, high elongation and excellent fatigue resistance, and exhibits low edge chipping rate, low wire breakage rate and high service life in the cutting of silicon nitride ceramic substrates. Attached Figure Description

[0032] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0033] Figure 1 The cross-sectional microstructure of the tungsten-cerium alloy wire prepared in Example 1 is shown.

[0034] Figure 2 The cross-sectional microstructure of the tungsten-cerium alloy wire prepared in Example 2 is shown.

[0035] Figure 3 The cross-sectional microstructure of the tungsten-cerium alloy wire prepared for Comparative Example 2 is shown.

[0036] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0037] The technical solutions in the embodiments will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0038] According to a first aspect of this application, this application provides a method for preparing tungsten-cerium alloy wire, comprising the following steps:

[0039] S1. A cerium-containing solution is mixed with ammonium paratungstate using a spray mixing method, and then dried to obtain a mixture;

[0040] Preferably, a cerium-containing solution is prepared using a soluble cerium salt, wherein the mass fraction of cerium in the cerium-containing solution is 6.5% to 10%, and the mass ratio of the cerium-containing solution to ammonium paratungstate is 0.24:1 to 0.36:1; the drying temperature is 70 to 90°C.

[0041] Specifically, the mass fraction of cerium in the cerium-containing solution can be any one of 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, or 10%, or any two of these values. The mass ratio of the cerium-containing solution to ammonium paratungstate can be any one of 0.24:1, 0.27:1, 0.30:1, 0.33:1, or 0.36:1, or any two of these values.

[0042] S2. Calcine the mixture to obtain oxide composite powder. The calcination temperature is ≤900℃.

[0043] Preferably, the calcination includes a first stage calcination, a second stage calcination, and a third stage calcination, wherein the temperature of the first stage calcination is 200~220℃ and the time is 1.5~2h, the temperature of the second stage calcination is 350~400℃ and the time is 2~2.5h, and the temperature of the third stage calcination is 750~900℃ and the time is 3~4h.

[0044] Specifically, the temperature for the first stage of calcination can be any one or a range between two of 200℃, 205℃, 210℃, 215℃, and 220℃, and the time can be any one or a range between two of 1.5h, 1.6h, 1.7h, 1.8h, 1.9h, and 2h. The temperature for the second stage of calcination can be any one or a range between two of 350℃, 360℃, 370℃, 380℃, 390℃, and 400℃. The time range can be any one or any two of 2h, 2.1h, 2.2h, 2.3h, 2.4h, and 2.5h. The calcination temperature of the third stage can be any one or any two of 750℃, 780℃, 820℃, 850℃, 880℃, and 900℃. The time can be any one or any two of 3h, 3.2h, 3.4h, 3.6h, 3.8h, and 4h.

[0045] S3. The oxide composite powder is reduced in a hydrogen atmosphere with a flow rate of 20~28L / min to obtain cerium-tungsten powder. The reduction temperature is 800~1050℃ and the time is 3~3.5h.

[0046] Specifically, the reduction temperature can be any one or a range between any two of 800℃, 850℃, 900℃, 950℃, 1000℃, and 1050℃, the time can be any one or a range between any two of 3h, 3.1h, 3.2h, 3.3h, 3.4h, and 3.5h, and the hydrogen flow rate can be any one or a range between any two of 20L / min, 22L / min, 24L / min, 26L / min, and 28L / min.

[0047] S4. The cerium-containing tungsten powder is isostatically pressed at a pressure of 170~200MPa to obtain a compact.

[0048] Specifically, the pressure can be any one of 170MPa, 180MPa, 190MPa, 200MPa, or any range between two of them.

[0049] S5. The compact is sintered in a hydrogen atmosphere with a flow rate of 3~5L / min to obtain a tungsten rod with a diameter of 19.5±0.3mm. The segmented sintering includes a first stage sintering and a second stage sintering. The temperature of the first stage sintering is 1500~1600℃ and the time is 1~1.5h. The temperature of the second stage sintering is 2300~2450℃ and the time is 5~8h.

[0050] Specifically, the sintering temperature in the first stage can be any one or a range between 1500℃, 1520℃, 1540℃, 1560℃, 1580℃, and 1600℃, and the sintering time can be any one or a range between 1h, 1.1h, 1.2h, 1.3h, 1.4h, and 1.5h. The sintering temperature in the second stage can be any one or a range between 2300℃, 2350℃, 2400℃, and 2450℃, and the sintering time can be any one or a range between 5h, 6h, 7h, and 8h. The hydrogen flow rate can be any one or a range between 3L / min, 3.5L / min, 4L / min, 4.5L / min, and 5L / min, and the diameter of the tungsten rod can be any one or a range between 19.2mm, 19.4mm, 19.5mm, 19.7mm, and 19.8mm.

[0051] S6. Roll the tungsten rod at a temperature of 1400~1800℃ to obtain a diameter of 9±0.2mm; then subject the tungsten rod to electrical pulse treatment at a temperature of 700~900℃ for 23~26s; next, forge the tungsten rod at a feed rate of 1.2~3m / min and a forging speed of 1500~2400 times / min to obtain a diameter of 3.6±0.2mm; finally, draw the tungsten rod to obtain a tungsten-cerium alloy wire with a diameter of 20~28μm.

[0052] Specifically, the rolling temperature can be any one or any two of 1400℃, 1500℃, 1600℃, 1700℃, and 1800℃; the diameter of the rolled tungsten rod can be any one or any two of 8.8mm, 8.8mm, 9.0mm, 9.1mm, and 9.2mm; the electrical pulse treatment temperature can be any one or any two of 700℃, 750℃, 800℃, 850℃, and 900℃; and the forging feed rate can be 1.2m / min, 1.5m / min, 2m / min, or 2.5m / min. The forging speed can be any one of 1500 times / min, 1800 times / min, 2000 times / min, 2200 times / min, 2400 times / min, or any two of these ranges. The diameter of the forged tungsten rod can be any one of 3.4 mm, 3.6 mm, 3.6 mm, 3.7 mm, 3.8 mm, or any two of these ranges. The diameter of the tungsten-cerium alloy wire can be any one of 20 μm, 22 μm, 24 μm, 26 μm, 28 μm, or any two of these ranges.

[0053] According to a second aspect of this application, this application provides a tungsten-cerium alloy wire, which is obtained by the above-described method for preparing tungsten-cerium alloy wire.

[0054] Preferably, the tungsten-cerium alloy wire has a tensile strength ≥4800MPa and an elongation of 3%~15%.

[0055] More preferably, the tungsten-cerium alloy wire has a tensile strength ≥6500MPa and an elongation of 8%~15%.

[0056] Preferably, the tungsten-cerium alloy wire is tested at 4000MPa using a fatigue testing machine, and its fatigue life exceeds 30,000 cycles.

[0057] More preferably, the tungsten-cerium alloy wire was tested at 4000 MPa using a fatigue testing machine, and its fatigue life exceeded 60,000 cycles.

[0058] The technical solution of this application will be further described below with reference to specific embodiments.

[0059] Example 1

[0060] A method for preparing a tungsten-cerium alloy wire includes the following steps:

[0061] S1. A cerium-containing solution with a cerium element mass fraction of 6.5% was prepared using Ce(NO3)3·6H2O. The cerium-containing solution was mixed with ammonium paratungstate at a mass ratio of 0.24:1 using a spray mixing method, and then dried at 80℃ to obtain a mixture.

[0062] S2. The mixture is calcined in stages, with the first stage calcination temperature at 210℃ for 1.5h, the second stage calcination temperature at 350℃ for 2h, and the third stage calcination temperature at 750℃ for 4h to obtain oxide composite powder.

[0063] S3. The oxide composite powder is reduced in a hydrogen atmosphere with a flow rate of 28 L / min to obtain cerium-tungsten powder. The reduction temperature is 1050℃ and the time is 3h.

[0064] S4. The cerium-containing tungsten powder is isostatically pressed at a pressure of 200 MPa to obtain a compact.

[0065] S5. The compact is sintered in a hydrogen atmosphere with a flow rate of 5L / min in stages to obtain a tungsten rod with a diameter of 19.7mm. The first stage of sintering is carried out at a temperature of 1500℃ for 1.5h, and the second stage of sintering is carried out at a temperature of 2300℃ for 7h.

[0066] S6. The tungsten rod is rolled at 1600℃ to a diameter of 9.2mm. Then, the tungsten rod is subjected to electrical pulse treatment at 900℃ for 23s. Next, the tungsten rod is forged at a feed rate of 2.3m / min and a forging speed of 2000 times / min. The diameter of the tungsten rod after forging is 3.6mm. Finally, the tungsten rod is drawn to obtain a tungsten-cerium alloy wire with a diameter of 28.4μm.

[0067] The tungsten-cerium alloy wire prepared in this embodiment was tested, and its cross-sectional microstructure is as follows: Figure 1 As shown, its microstructure is uniform, its tensile strength is 6545MPa, its elongation is 11%, and it fractures after 75760 fatigue tests at 4000MPa.

[0068] Example 2

[0069] A method for preparing a tungsten-cerium alloy wire includes the following steps:

[0070] S1. A cerium-containing solution with a cerium element mass fraction of 6.5% was prepared using Ce(NO3)3·6H2O. The cerium-containing solution was mixed with ammonium paratungstate at a mass ratio of 0.36:1 using a spray mixing method, and then dried at 80℃ to obtain a mixture.

[0071] S2. The mixture is calcined in stages, with the first stage calcination temperature at 200℃ for 2 hours, the second stage calcination temperature at 380℃ for 2 hours, and the third stage calcination temperature at 900℃ for 3.5 hours to obtain oxide composite powder.

[0072] S3. The oxide composite powder is reduced in a hydrogen atmosphere with a flow rate of 24 L / min to obtain cerium-tungsten powder. The reduction temperature is 800℃ and the time is 3.5 h.

[0073] S4. The cerium-containing tungsten powder is isostatically pressed at a pressure of 170 MPa to obtain a compact.

[0074] S5. The compact is sintered in a hydrogen atmosphere with a flow rate of 4L / min in a segmented manner to obtain a tungsten rod with a diameter of 19.5mm. The first stage of sintering is carried out at a temperature of 1550℃ for 1.5h, and the second stage of sintering is carried out at a temperature of 2450℃ for 5h.

[0075] S6. The tungsten rod is rolled at 1800℃ to a diameter of 8.8mm. Then, the tungsten rod is subjected to electrical pulse treatment at 700℃ for 25s. Next, the tungsten rod is forged at a feed rate of 3m / min and a forging speed of 2400 times / min. The diameter of the forged tungsten rod is 3.8mm. Finally, the tungsten rod is drawn to obtain a tungsten-cerium alloy wire with a diameter of 25.7μm.

[0076] The tungsten-cerium alloy wire prepared in this embodiment was tested, and its cross-sectional microstructure is as follows: Figure 2 As shown, its microstructure is uniform, its tensile strength is 6710MPa, its elongation is 8%, and it fractures after 67360 fatigue tests at 4000MPa.

[0077] Example 3

[0078] A method for preparing a tungsten-cerium alloy wire includes the following steps:

[0079] S1. A cerium-containing solution with a cerium element mass fraction of 6.5% was prepared using Ce(NO3)3·6H2O. The cerium-containing solution was mixed with ammonium paratungstate at a mass ratio of 0.30:1 using a spray mixing method, and then dried at 80℃ to obtain a mixture.

[0080] S2. The mixture is calcined in stages, wherein the first stage of calcination is carried out at a temperature of 220℃ for 2 hours, the second stage of calcination is carried out at a temperature of 400℃ for 2.5 hours, and the third stage of calcination is carried out at a temperature of 830℃ for 3 hours to obtain oxide composite powder.

[0081] S3. The oxide composite powder is reduced in a hydrogen atmosphere with a flow rate of 20 L / min to obtain cerium-tungsten powder. The reduction temperature is 900℃ and the time is 3.5 h.

[0082] S4. The cerium-containing tungsten powder is isostatically pressed at a pressure of 185 MPa to obtain a compact.

[0083] S5. The compact is sintered in a hydrogen atmosphere with a flow rate of 3L / min in a segmented manner to obtain a tungsten rod with a diameter of 19.2mm. The first stage of sintering is carried out at a temperature of 1600℃ for 1h, and the second stage of sintering is carried out at a temperature of 2400℃ for 8h.

[0084] S6. The tungsten rod is rolled at 1400℃ to a diameter of 9.0 mm. Then, the tungsten rod is subjected to electrical pulse treatment at 800℃ for 26 seconds. Next, the tungsten rod is forged at a feed rate of 1.2 m / min and a forging speed of 1500 times / min. The diameter of the tungsten rod after forging is 3.4 mm. Finally, the tungsten rod is drawn to obtain a tungsten-cerium alloy wire with a diameter of 22.9 μm.

[0085] The tungsten-cerium alloy wire prepared in this embodiment was tested and found to have a uniform microstructure, a tensile strength of 6880 MPa, an elongation of 15%, and to break after 63,140 fatigue tests at 4000 MPa.

[0086] Example 4

[0087] A method for preparing a tungsten-cerium alloy wire includes the following steps:

[0088] S1. A cerium-containing solution with a cerium element mass fraction of 6.5% was prepared using Ce(NO3)3·6H2O. The cerium-containing solution was mixed with ammonium paratungstate at a mass ratio of 0.27:1 using a spray mixing method, and then dried at 80℃ to obtain a mixture.

[0089] S2. The mixture is calcined in stages, with the first stage calcination temperature at 210℃ for 1.5h, the second stage calcination temperature at 400℃ for 2h, and the third stage calcination temperature at 900℃ for 3.5h to obtain oxide composite powder.

[0090] S3. The oxide composite powder is reduced in a hydrogen atmosphere with a flow rate of 28 L / min to obtain cerium-tungsten powder. The reduction temperature is 950℃ and the time is 3h.

[0091] S4. The cerium-containing tungsten powder is isostatically pressed at a pressure of 190 MPa to obtain a compact.

[0092] S5. The compact is sintered in a hydrogen atmosphere with a flow rate of 4L / min in a segmented manner to obtain a tungsten rod with a diameter of 19.8mm. The first stage of sintering is carried out at a temperature of 1600℃ for 1h, and the second stage of sintering is carried out at a temperature of 2350℃ for 8h.

[0093] S6. The tungsten rod is rolled at 1500℃ to a diameter of 9.1mm. Then, the tungsten rod is subjected to electrical pulse treatment at 800℃ for 26s. Next, the tungsten rod is forged at a feed rate of 2.5m / min and a forging speed of 1800 times / min, resulting in a diameter of 3.8mm. Finally, the tungsten rod is drawn to obtain a tungsten-cerium alloy wire with a diameter of 28.1μm.

[0094] The tungsten-cerium alloy wire prepared in this embodiment was tested and found to have a uniform microstructure, a tensile strength of 6516 MPa, an elongation of 8%, and to break after 73,682 fatigue tests at 4000 MPa.

[0095] Example 5

[0096] A method for preparing a tungsten-cerium alloy wire includes the following steps:

[0097] S1. A cerium-containing solution with a cerium element mass fraction of 6.5% was prepared using Ce(NO3)3·6H2O. The cerium-containing solution was mixed with ammonium paratungstate at a mass ratio of 0.15:1 using a spray mixing method, and then dried at 80℃ to obtain a mixture.

[0098] S2. The mixture is calcined in stages, with the first stage calcination temperature at 210℃ for 1.5h, the second stage calcination temperature at 350℃ for 2h, and the third stage calcination temperature at 750℃ for 4h to obtain oxide composite powder.

[0099] S3. The oxide composite powder is reduced in a hydrogen atmosphere with a flow rate of 28 L / min to obtain cerium-tungsten powder. The reduction temperature is 1050℃ and the time is 3h.

[0100] S4. The cerium-containing tungsten powder is isostatically pressed at a pressure of 200 MPa to obtain a compact.

[0101] S5. The compact is sintered in a hydrogen atmosphere with a flow rate of 5L / min in stages to obtain a tungsten rod with a diameter of 19.7mm. The first stage of sintering is carried out at a temperature of 1500℃ for 1.5h, and the second stage of sintering is carried out at a temperature of 2300℃ for 7h.

[0102] S6. The tungsten rod is rolled at 1600℃ to a diameter of 9.2mm. Then, the tungsten rod is subjected to electrical pulse treatment at 900℃ for 23s. Next, the tungsten rod is forged at a feed rate of 2.3m / min and a forging speed of 2000 times / min. The diameter of the tungsten rod after forging is 3.6mm. Finally, the tungsten rod is drawn to obtain a tungsten-cerium alloy wire with a diameter of 28.4μm.

[0103] The tungsten-cerium alloy wire prepared in this embodiment was tested and found to have a uniform microstructure, a tensile strength of 5248 MPa, an elongation of 3%, and to break after 36285 fatigue tests at 4000 MPa.

[0104] Example 6

[0105] A method for preparing a tungsten-cerium alloy wire includes the following steps:

[0106] S1. A cerium-containing solution with a cerium element mass fraction of 6.5% was prepared using Ce(NO3)3·6H2O. The cerium-containing solution was mixed with ammonium paratungstate at a mass ratio of 0.24:1 using a spray mixing method, and then dried at 80℃ to obtain a mixture.

[0107] S2. The mixture is calcined at 900℃ for 3.5 hours to obtain oxide composite powder;

[0108] S3. The oxide composite powder is reduced in a hydrogen atmosphere with a flow rate of 28 L / min to obtain cerium-tungsten powder. The reduction temperature is 1050℃ and the time is 3h.

[0109] S4. The cerium-containing tungsten powder is isostatically pressed at a pressure of 200 MPa to obtain a compact.

[0110] S5. The compact is sintered in a hydrogen atmosphere with a flow rate of 5L / min in stages to obtain a tungsten rod with a diameter of 19.7mm. The first stage of sintering is carried out at a temperature of 1500℃ for 1.5h, and the second stage of sintering is carried out at a temperature of 2300℃ for 7h.

[0111] S6. The tungsten rod is rolled at 1600℃ to a diameter of 9.2mm. Then, the tungsten rod is subjected to electrical pulse treatment at 900℃ for 23s. Next, the tungsten rod is forged at a feed rate of 2.3m / min and a forging speed of 2000 times / min. The diameter of the tungsten rod after forging is 3.6mm. Finally, the tungsten rod is drawn to obtain a tungsten-cerium alloy wire with a diameter of 28.4μm.

[0112] The tungsten-cerium alloy wire prepared in this embodiment was tested and found to have an uneven microstructure (cerium and tungsten formed a second phase during calcination), a tensile strength of 4868 MPa, an elongation of 5%, and fractured after 31735 fatigue tests at 4000 MPa.

[0113] Comparative Example 1

[0114] Except for the reduction temperature of 500°C and the time of 5h in step S3, the comparative example is the same as Example 1. Due to the low reduction temperature, the tungsten oxide was not completely reduced, resulting in impure tungsten powder with increased brittleness. The forging and drawing processes resulted in frequent breakage, making it impossible to prepare tungsten-cerium alloy wire.

[0115] Comparative Example 2

[0116] Except for step S5, which did not employ segmented sintering but instead involved sintering at 2400℃ for 9 hours, this comparative example was identical to Example 1. The resulting tungsten rods had high oxygen content and a high wire breakage rate during drawing (out of 10 drawn wires, 7 broke during the drawing process). The cross-sectional microstructure of the tungsten-cerium alloy wire prepared in this comparative example was analyzed as follows: Figure 3 As shown, its microstructure contains pores.

[0117] Comparative Example 3

[0118] Except for the third stage calcination temperature of 1000℃ and the time of 2h in step S2, the comparative example is the same as Example 1. Frequent breakage during the forging and drawing processes made it impossible to prepare tungsten-cerium alloy wire.

[0119] Comparative Example 4

[0120] Except for the second stage sintering temperature of 2200℃ and the time of 8h in step S5, the comparative example is the same as Example 1. After rolling, the tungsten rod has many cracks, and it breaks frequently during deformation and drawing processes, making it impossible to prepare tungsten-cerium alloy wire.

[0121] Comparative Example 5

[0122] Except for step S1, in which a Ce(NO3)3·6H2O solid mixed with ammonium paratungstate solution was used to prepare the mixture, the comparative example was the same as in Example 1. Frequent breakage occurred during the forging and drawing processes, making it impossible to prepare tungsten alloy wire.

[0123] This application proposes a tungsten-cerium alloy wire and its preparation method, which produces the following beneficial effects: by solid-liquid doping with cerium, the uniform distribution of cerium in the alloy wire is achieved, overcoming the problems of uneven cerium distribution and easy agglomeration in the traditional mechanical mixing method; through a two-stage sintering process, the oxygen content in the tungsten rod is significantly reduced, and the density and mechanical properties are improved; the prepared tungsten-cerium alloy wire has excellent tensile strength, high elongation and excellent fatigue resistance, and exhibits low edge chipping rate, low wire breakage rate and high service life in the cutting of silicon nitride ceramic substrates.

[0124] The above description is only a preferred embodiment of this application and does not limit the patent scope of this application. All equivalent structural transformations made using the content of this application's specification under the inventive concept of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A method for preparing a tungsten-cerium alloy wire, characterized in that, Includes the following steps: S1. A cerium-containing solution is mixed with ammonium paratungstate using a spray mixing method, and then dried to obtain a mixture; S2. The mixture is calcined to obtain oxide composite powder, wherein the calcination temperature is ≤900℃; S3. The oxide composite powder is reduced in a hydrogen atmosphere to obtain cerium-tungsten powder. The reduction temperature is 800~1050℃ and the time is 3~3.5h. S4. The cerium-containing tungsten powder is subjected to isostatic pressing to obtain a pressed blank; S5. The pressed blank is sintered in a hydrogen atmosphere to obtain a tungsten rod. The segmented sintering includes a first stage sintering and a second stage sintering. The temperature of the first stage sintering is 1500~1600℃ and the time is 1~1.5h. The temperature of the second stage sintering is 2300~2450℃ and the time is 5~8h. S6. The tungsten rod is rolled, subjected to electrical pulse treatment, forged and drawn to obtain a tungsten-cerium alloy wire with a diameter of 20~28μm; The tungsten-cerium alloy wire has a tensile strength ≥4800MPa and an elongation of 3%~15%.

2. The method for preparing tungsten-cerium alloy wire according to claim 1, characterized in that, Step S1 further includes preparing the cerium-containing solution using a soluble cerium salt, wherein the mass fraction of cerium in the cerium-containing solution is 6.5% to 10%, and the mass ratio of the cerium-containing solution to the ammonium paratungstate is 0.24:1 to 0.36:

1.

3. The method for preparing tungsten-cerium alloy wire according to claim 1, characterized in that, In step S2, the calcination includes a first stage calcination, a second stage calcination, and a third stage calcination. The first stage calcination is carried out at a temperature of 200-220°C for 1.5-2 hours, the second stage calcination is carried out at a temperature of 350-400°C for 2-2.5 hours, and the third stage calcination is carried out at a temperature of 750-900°C for 3-4 hours.

4. The method for preparing tungsten-cerium alloy wire according to claim 1, characterized in that, In step S3, the flow rate of hydrogen in the hydrogen atmosphere is 20~28L / min.

5. The method for preparing tungsten-cerium alloy wire according to claim 1, characterized in that, In step S4, the pressure during isostatic pressing is 170~200MPa.

6. The method for preparing tungsten-cerium alloy wire according to claim 1, characterized in that, In step S5, the flow rate of hydrogen in the hydrogen atmosphere is 3~5L / min.

7. The method for preparing tungsten-cerium alloy wire according to claim 1, characterized in that, In step S6, the rolling temperature is 1400~1800℃; The temperature during the electrical pulse processing is 700~900℃, and the time is 23~26s; The feeding speed during the forging process is 1.2~3m / min, and the forging speed is 1500~2400 times / min.

8. The method for preparing tungsten-cerium alloy wire according to claim 7, characterized in that, In step S5, the diameter of the tungsten rod is 19.5 ± 0.3 mm; In step S6, the diameter of the tungsten rod after rolling is 9±0.2mm; In step S6, the diameter of the tungsten rod after forging is 3.6 ± 0.2 mm.

9. A tungsten-cerium alloy wire, characterized in that, It is obtained by the preparation method of tungsten-cerium alloy wire according to any one of claims 1 to 8.

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